There are websites that claim to own formulas that outperform the market. Examples of these websites are - Zacks Investment Research or Investors Business Daily. Each keep a list of equities that they recommend to buy and sell at specific moments in time. If you look at their websites, they claim to provide a 30%+ return on investment. These claims are bold.
I will like to know if these companies have to provide proof of these claims or if someone knows already they are not correct. Is there a sanctioning body that accredits or oversees these groups?